Synthesis, crystal structure, Hirshfeld surface analysis, and energy framework of bis{3-(4-bromophenyl)-5-[6-(1H-pyrazol-1-yl)pyridin-2-yl]-4H-1,2,4-triazol-4-ido}nickel(II) methanol disolvate and comparison with its chloro-substituted analogue

The unit cell of the title compound, [Ni(C 16 H 10 BrN 6 ) 2 ]·2CH 3 OH, contains a neutral complex and two methanol molecules. The Ni II ion adopts a pseudooctahedral geometry, coordinated by two tridentate ligands via pyrazole, pyridine, and triazole N atoms. The average Ni—N bond length is 2.097 (4) Å. In the crystal, molecules form supramolecular chains through weak C–H...π interactions and further assemble into diperiodic layers via C—H...N/C interactions. Hirshfeld surface analysis shows H...H (32.1%), H...C/C...H (27.3%), H...N/N...H (14.9%), and H...Br/Br...H (14.6%) contacts. Interaction energies were evaluated using HF/3–21 G energy frameworks analysis. Structural parameters were compared to those of the chloro-containing analogue, and the effect of substituent variation was discussed.